ECMAScript 4:The Reckoning

John Resig

2007: ShibuyaJS

The DirectionECMAScript 4

JavaScript 2 ActionScript 4

Tamarin

JScript Etc.

Screaming Monkey

KJS (Apple)

Opera

A TON of new features!

Classes✦ class Programmer {

var name; var city = “Boston, MA”; const interest = “computers”; function work() {}}

✦ var p = new Programmer;p.name = “John”;p.work();p.work.apply( someotherp );p.interest = “science”; // Errorp.lastName = “Resig”; // Error

Catch-Alls✦ dynamic class Programmer {

meta function get(name) { ... } meta function set(name, value) { alert(“Setting “ + name + “ to “ + value); }}

✦ var p = new Programmerp.name = “John”;// alert(“Setting name to John”);

Inheritance✦ class Artist {

function draw() { alert(“Drawing!”); }}class Designer extends Artist { override function draw() { alert(“Designing!”); }}

✦ var d = new Designerd.draw();// alert(“Designing!”);

Interfaces✦ Verify that a class implements another✦ interface Artist {

function draw();}class Designer implements Artist { function draw() { alert(“Designing!”); }}

✦ var d = new Designer();if ( d is Artist ) alert(“Designers are Artists!”);

Too much?

The new features are important!They give the language more power andmake large applications easier to create.

Plus applications will be able to get faster!

The new features are important!They give the language more power andmake large applications easier to create.

(Plus it’s close to what we’ve alreadydone in ActionScript!)

There are too many new features!Not enough attention was paid to security.

Not enough attention was paid to security.

We don’t like it.

WAR!YES NO

The DirectionECMAScript 4

JavaScript 2 ActionScript 4

Tamarin

JScript Etc.

Screaming Monkey

KJS (Apple)

Opera

Compromise:NO SYNTAX CHANGES

Compromise:LESS NEW FEATURES

ECMAScript 5!!

JSON Parsing

• JSON.parse(“true”) -> true

• JSON.stringify(true) -> “true”

Strict Mode

• (function(){ “use strict”;

// NO eval, with, etc.})();

Object Properties• var obj = {};

• Object.defineProperty( obj, "value", {  value: true,  writable: false,  enumerable: true,  configurable: true});

• (function(){  var name = "John";    Object.defineProperty( obj, "name", {    get: function(){ return name; },    set: function(value){ name = value; }  });})();

HARMONY:Build off of ES5

What about Tamarin?

Don’t need it!

COMPETITION:Everyone got faster!Don’t need a new

language to get faster.

More about ES5

• http://ejohn.org/blog/ecmascript-5-objects-and-properties/

• http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/

Processing.jsJohn Resig

Processing✦ Data visualization programming language

✦ Built on top of Java

✦ I ported it to JavaScript in 2008!

✦ Crude port of the Processing Language +

✦ Porting the 2D Processing API

✦ All runs in JavaScript on top of HTML 5 Canvas

✦ Works in all browsers (IE with excanvas)

The Language✦ Strictly typed✦ Has classes, inheritance✦ A bunch of globally-accessible functions

✦ (Very flat API)✦ setup() and draw() methods

✦ Very OpenGL-like✦ draw() is called continually at a specific

framerate

Draw A Line w/ Mouse✦ While you hold the mouse down, draw a

line from the previous mouse point✦ http://ejohn.org/apps/processing.js/

examples/topics/continuouslines.html✦ void setup() {

size(200, 200); background(102);}

void draw() { stroke(255); if (mousePressed) { line(mouseX, mouseY, pmouseX, pmouseY); }}

Drawing✦ Different drawing methods:

✦ line()✦ rect()✦ arc()✦ ellipse()✦ point()✦ quad()✦ triangle()✦ bezier()

✦ All use stroke(), strokeWeight(), fill()

The Canvas✦ OpenGL-y✦ Mutate the canvas rendering:

✦ translate()✦ scale()✦ rotate()

✦ Save and Restore the state of the canvas:✦ pushMatrix()✦ popMatrix()

✦ http://ejohn.org/apps/processing.js/examples/basic/arm.html

Shapes✦ A series of vertices, built into a shape✦ fill(127);

beginShape(); for (int i=0; i<segments; i++){ vertex(ground[i].x1, ground[i].y1); vertex(ground[i].x2, ground[i].y2); } vertex(ground[segments-1].x2, height); vertex(ground[0].x1, height); endShape(CLOSE);

Classes✦ Hold data, do inheritance✦ http://ejohn.org/apps/processing.js/

examples/topics/reflection2.html✦ class Ground {

float x1, y1, x2, y2, x, y, len, rot; Ground(){ } Ground(float x1, float y1, float x2, float y2) { this.x1 = x1; this.y1 = y1; this.x2 = x2; this.y2 = y2; x = (x1+x2)/2; y = (y1+y2)/2; len = dist(x1, y1, x2, y2); rot = atan2((y2-y1), (x2-x1)); }}

ECMAScript 4??

Processing.js 1.0!✦ Just released yesterday!✦ Full API parity with Processing✦ ALSO✦ Full WebGL/3D support!✦ A great API for doing graphical work.

jQuery MobileJohn Resig

The Missing Gap

• Almost all mobile web development focuses on modern WebKit

• There are far too many other platforms

• Blackberry, Opera, Windows Mobile, Mobile Firefox, Symbian, etc.

• jQuery Mobile works everywhere - and without sacrificing experience.

Phase 1: jQuery Core

• We’re working to make jQuery core work on all the popular mobile browsers.

• Building out our test suite and continuous integration testing.

• Using TestSwarm to automate our testing across all platforms.

• Fixing mobile bugs in core.

Phase 2: jQuery Mobile

• A complete framework for building mobile web sites and applications.

• Provide all the widgets and layout components necessary to build mobile sites.

• Built on the principles of progressive enhancement